Updated at 9:16 p.m. ET: Officials have called in the Bureau of Alcohol, Tobacco, Firearms and Explosives to investigate a thunderous explosion that killed two and left 27 homes uninhabitable in a south Indianapolis neighborhood late Saturday night, NBC affiliate WTHR reported.

The blast was reported shortly after 11 p.m. near South Sherman Drive and Stop 11 Road on the south side of Indianapolis, WTHR said.

"Multiple houses engulfed in flames. Even the police officers that got to the scene before I did were not sure what happened. Kind of a surreal scene, even for police officers," Marion County Sheriff John Layton told the station.

Two houses were leveled by an explosion that sparked a fire and killed two people early Sunday morning. The powerful nighttime blast shattered windows, crumpled walls and could be felt at least three miles away.

The cause of the explosion and fires wasn't immediately clear, but Indianapolis Mayor Greg Ballard dismissed reports of a possible plane crash as he arrived at the scene. Fire officials said separately that investigators would be checking whether natural gas was possibly involved but they had no further details on what was behind the blast that sent tall flames skyward.

Ballard said at least two homes had been destroyed by the powerful blast and that the damage went on "for blocks on end."

Television video showed tall flames shooting overhead and spreading to numerous homes shortly after the blast reported around 11 p.m. Saturday. Hours after the flames pierced the skyline, firefighters had begun containing the flames and thick clouds of gray smoke billowed overhead.

Matt Kryger / AP

Authorities say a loud explosion has leveled a home in Indianapolis and set four others ablaze in a neighborhood, causing several injuries.

"It was so strong that it clearly had an effect for blocks," Ballard said from the area. Beyond the burning homes there was wider damage in the neighborhood: windows shattered in nearby homes, walls caved in and garage doors were knocked off their hinges.

Residents were told to evacuate to a nearby elementary school and people could be seen shivering in white blankets handed out to them as they moved off.